The combination of two or more chemical elements, of which at least one is a metal. Usually possesses properties different from those of components (i.e. cast iron contains iron, carbon, and silicon).

Annealing

:

A process involving heating and slow cooling applied in order to alter the mechanical or physical properties, particularly hardness-softening process.

Back Draft

:

A reverse taper from the designed direction of draw from a pattern or core box. It prevents removal of a pattern from a mold without damage to the mold (tear-ups).

Bars

:

Metal supports placed in a flask, usually the cope to reinforce the sand.

Bath

:

Molten metal pool in a ladle or furnace.

BHN

:

Brinell Hardness Number.

Blasting

:

A process for cleaning or finishing metal objects by the high velocity impingement of sand or hard metal shot against the surface of the objects.

Blind Riser

:

A riser not opened to the atmosphere (see Riser).

Blower-core

:

A machine using air pressure to fill a core box with sand.

Boss

:

A projection of circular cross-section on a casting, usually intended for drilling and tapping for attached parts.

Brinell Hardness

:

The value of hardness of a metal on an arbitrary scale representing kg/mm2.

Burn-in or burn-on

:

A misnomer usually indicating metal penetration into molding and core sand resulting in a mixture of metal and sand on a casting.

Cast Iron

:

A term used to describe a series of ferrous alloys containing over 1.74% of carbon.

Casting

:

Metal object obtained by pouring molten metal into a mold. It also is the act of pouring metal.

Chaplet

:

Metal support used in molds to help hold cores in proper position.

Chilled edge or Surface (Crust)

:

Rapid cooling of thin sections. It causes a very hard and brittle condition that is detrimental to machining.

Choke

:

A restriction in the feed system that controls the flow rate of metal into the mold cavity.

Coke

:

Fuel used in a cupola to melt charge materials. Source of some carbon found in iron.

Cope

:

Upper or topmost section of a mold, flask, or pattern.

Core Box

:

Wood, metal, or plastic box, the cavity of which has the shape of the desired core which is to be made therein.

Core Print

:

Projections on a pattern that form and locate cores in a mold. Also, projections on core or area in mold for same purpose.

Core Rod

:

Steel rods imbedded in a core used to reinforce the core.

Cupola

:

A vertical shaft furnace lined with refractories used to produce cast iron by high temperature melting of metallic and mineral charge materials.

Die Casting

:

Forcing molten metal into permanent molds (Also, pressure casting).

Draft

:

The taper on vertical surfaces of a pattern which allows easy withdrawal of pattern from compacted sand mixture.

Drag

:

Lower or bottom section of a mold, pattern, or flask.

Dross

:

Metal oxides and other scum on the surface of molten metal. It is mostly a non-ferrous term.

Ductile Iron

:

Iron in which carbon is in the form of spherical nodules (also called Nodular Iron).

Feed Metal

:

The volume of molten metal from which a casting feeds as it shrinks (contracts) during solidification.

Fin

:

A thin projection of metal from the casting, formed as a result of imperfect mold or core joints.

Flask

:

A molding box into which molding sand is placed against the pattern while the box surrounds the pattern. It usually consists of a top and bottom (cope and drag).

Flat-back

:

A pattern with a flat surface at the joint of the mold. It lies wholly within the drag or cope and this joint of the mold is a plane surface.

Flow-off

:

A large vent, usually located at the high point of the mold cavity. In addition to letting air and mold gasses escape during a pour, the flow-off fills with metal and is allowed to run or flow during the final stage of pouring.

Fluidity

:

The ability of molten metal to flow readliy.

Founding

:

The sciences of melting and casting metals into useful objects that serve the needs of industry. It is better known as metal casting.

Gagger

:

A metal piece of irregular shape (usually an L shape) used to reinforce and support sand in deep pockets of molds. There are two types: straight or hooked (cast or steel rods).

Gate

:

The portion of the feed system where molten metal enters the mold cavity. It is also called an ingate.

Gating System

:

The complete assembly of sprues, runners, and gates in the mold.

Green Sand

:

Tempered i.e., moistened molding sand

Green Strength

:

The strength of molding sand containing moisture.

Guide Pin

:

The pin on a flask used to locate the cope in the proper place on the drag. Also to locate cheeks

Head

:

The pressure exerted by a fluid, as a head of molten metal.

Heel

:

Metal left in a ladle after pouring or in a furnace after or between tapping.

Holding Furnace

:

A vessel to hold and keep hot certain amounts of molten metal.

Inoculent

:

Materials which when added to molten metal, modify the structure and thereby change the physical and mechanical properties.

Investment Casting

:

A process where patterns are removed by a melting or burning out process (i.e. lost wax process).

Jolt

:

To raise the flask filled with
sand and allow it to drop, thereby compacting the sand against the pattern.

Knock-off Riser

:

Riser with a small
attachment and can be knocked off with a hammer.

Ladle

:

Metal barrel-like receptacles
lined with a refractory material used to transport or pour molten metal.

Lap-gate

:

When the connection point of ingate to casting overlaps onto the cope surface (i.e. kiss-gate).

Loose Pieces

:

Part of a core box or pattern which remains embedded in the core or mold and is removed after lifting off the core box or drawing the pattern. Back Draft is avoided by this means.

Mold

:

The complete "box of sand" with the cavity inside and the gating system ready to accept the molten metal.

Mold Wash

:

Refractory emulsion coating used to coat cavity walls. It guards against penetration of metal into sand walls.

Muller

:

A type of sand mixing machine

Mulling

:

The thorough mixing of sand, water, and binding ingredients to form tempered, ready-to-use molding, or core sand.

Oil Sand Core

:

Core in which sand mass is bound by an oil-based binder.

Open Riser

:

Riser whose top is open to the atmosphere through the top of the mold.

Padding

:

The process of adding extra material to a cross-section of a casting wall, usually extending from a riser to ensure adequate feed to a localized area where shrinking would occur if the added material were not present.

Parting Line

:

The joint where mold separates to permit removal of the pattern. Separates cope and drag.

Pattern

:

A form of wood, metal, or plastic around which molding material is packed to produce a mold cavity for casting metals. Corresponds to shape desired for casting.

Permanent Mold

:

A long-life mold into which metal is poured by gravity

Pocket

:

A body of sand surrounded on all but one side by molten metal.

Pouring Basin, Cup, Runner Box

:

The portion of the gating system into which molten metal is introduced. Located on top of sprue or down gate.

Ram

:

Process of packing sand in a mold using a pneumatic or mechanized ramming device.

Returns

:

Metal in form of gates, sprues, risers, or defective castings which are put back into the melting cycle.

Riser

:

A reservoir of molten metal to supply a contracting, cooling casting with make-up metal. It is used to prevent internal or external voids due to shrinkage.

Riser, Blind

:

A riser which is not open to the atmosphere.

Runner

:

That portion of the feed system which carries molten metal from the sprue to the gates (i.e. the metal distribution system).

Runner Extension

:

That part of a runner which extends beyond the farthest ingate as a blind end. It acts as a dirt trap and is sometimes vented.

Scrap

:

Metal to be remelted because of some imperfection.

Shakeout

:

The process of removing sufficiently cooled castings from a mold.

Shell Mold Process

:

Molds and cores having shell-like structures using thermosetting resins as binders, heated patterns, and core boxes.

Shot

:

Metallic abrasive commonly used for cleaning casting surfaces.

Shrinkage

:

The difference in volume between liquid metal and solid metal in a given cavity.

Slag

:

An enlargement, dam, or protrusion in the gating or runner system in a mold for the purpose of preventing molten slag particles from entering the mold cavity.

Steel

:

An alloy of iron and carbon, containing less than 1.74% carbon.

Stool

:

Device used on molding machine to hold pattern plate or refractory block used to support a crucible in a crucible furnace.

Stress Raisers

:

Factors such as sharp changes in contour or surface defects which concentrate stresses locally.

Strike-Off

:

Operation of removing excess sand from top of core box of flask. Metal bar used for same purpose.

Stripping

:

Removing the pattern from the mold or core from core box.

Tear-Up

:

A defect caused by back draft, damaged pattern, or uneven drawing of a pattern.

Upset

:

An addition to any flask part to increase height or
depth.

Vent

:

A small opening through which gases can escape during the pouring of a mold.

Washes

:

Refractory coating applied to molds and cores to provide protection against penetration from molten metal.

Yield

:

Comparison of finished casting weight versus total weight of metal poured in a mold.